"The plot involved an upgrade of the underwear bomb that failed to detonate aboard a jetliner over Detroit on Dec. 25, 2009. This new bomb was also designed to be used in a passenger's underwear, but this time al-Qaida developed a more refined detonation system, U.S. officials said.

"The FBI is examining the latest bomb to see whether it could have passed through airport security and brought down an airplane, officials said. They said the device did not contain metal, meaning it probably could have passed through an airport metal detector.

"But it was not clear whether new body scanners used in many airports would have detected it.

"The would-be suicide bomber, based in Yemen, had not yet picked a target or bought his plane tickets when the CIA stepped in and seized the bomb, officials said. It's not immediately clear what happened to the alleged bomber."

Reuters adds that no airliner was ever at risk.

CNN reports that the plot was hatched to coincide with the anniversary of the killing of Osama bin Laden and had the signs of al-Qaida's master bomb maker Ibrahim Hassan al-Asiri. CNN also adds that the device was recovered.

Update at 5:25 p.m. ET. 'Adapting Its Tactics':

The AP reports that this bomb never made it on an airplane and did not cross security. However, CNN reports, the device was "nonmetallic," so it's unclear whether it would have made it through airport security.

Quoting an unnamed U.S. counterterrorism official, CNN says "the device is different from what was used by the 'underwear bomber' in 2009, but it was in the same category." The official tells CNN that the changes show al-Qaida "in the Arabian Peninsula is adapting its tactics."

Update at 5:19 p.m. ET. No Threat To The Public:

Backing up a bit, here's a bit more the White House's deputy National Security Council spokesperson Caitlin Hayden:

"While the President was assured that the device did not pose a threat to the public, he directed the Department of Homeland Security and law enforcement and intelligence agencies to take whatever steps necessary to guard against this type of attack. The disruption of this IED plot underscores the necessity of remaining vigilant against terrorism here and abroad."

Update at 5:09 p.m. ET. FBI In Possession Of Device:

In a statement, the FBI says the "improvised explosive device" was seized "overseas." The statement reads in part:

"The FBI currently has possession of the IED and is conducting technical and forensics analysis on it. Initial exploitation indicates that the device is very similar to IEDs that have been used previously by al Qaeda in the Arabian Peninsula (AQAP) in attempted terrorist attacks, including against aircraft and for targeted assassinations. The device never presented a threat to public safety, and the U.S. government is working closely with international partners to address associated concerns with the device."

Update at 5:01 p.m. ET. President Knew In April:

In a statement, the White Says the president was told about the "IED plot" in April by White House counterterrorism adviser John Brennan. The president was "assured that the device did not pose a threat to the public."

In its story, the AP reports that while this plot was unfolding, the White House and the Department of Homeland Security told Americans they had no new knowledge of "al-Qaida plots against the U.S. around the anniversary of bin Laden's death."